// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)

#pragma once

// periodic worker thread - periodically executes the given callback function.
//
// RAII over the owned thread:
//    creates the thread on construction.
//    stops and joins the thread on destruction (if the thread is executing a callback, wait for it
//    to finish first).

#include <chrono>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <thread>
namespace spdlog {
namespace details {

    class SPDLOG_API periodic_worker
    {
    public:
        template <typename Rep, typename Period> periodic_worker(const std::function<void()>& callback_fun, std::chrono::duration<Rep, Period> interval)
        {
            active_ = (interval > std::chrono::duration<Rep, Period>::zero());
            if (!active_)
            {
                return;
            }

            worker_thread_ = std::thread([this, callback_fun, interval]() {
                for (;;)
                {
                    std::unique_lock<std::mutex> lock(this->mutex_);
                    if (this->cv_.wait_for(lock, interval, [this] { return !this->active_; }))
                    {
                        return;  // active_ == false, so exit this thread
                    }
                    callback_fun();
                }
            });
        }
        periodic_worker(const periodic_worker&) = delete;
        periodic_worker& operator=(const periodic_worker&) = delete;
        // stop the worker thread and join it
        ~periodic_worker();

    private:
        bool active_;
        std::thread worker_thread_;
        std::mutex mutex_;
        std::condition_variable cv_;
    };
}  // namespace details
}  // namespace spdlog

#ifdef SPDLOG_HEADER_ONLY
#include "periodic_worker-inl.h"
#endif
